Bis-2-substituted-thiovinyl sulfones

ABSTRACT

Bis-(1-halo-2-alkylthioethyl) and bis-(1-halo-2-arylthioethyl) sulfones, having algicidal and fungicidal activity, are prepared by the addition of alkylsulfenyl or arylsulfenyl halides to divinyl sulfones. The sulfone products may be treated with base to produce bis-2-alkylthiovinyl or bis-2-arylthiovinyl sulfones, which also have algicidal and fungicidal activity.

DESCRIPTION OF THE PRIOR ART

Chemical Abstracts 68 59110t (1968) and 67 108135v (1967) disclose thepreparation of beta-substituted ethyl vinyl sulfones by the addition ofalcohols and mercaptans to divinyl sulfone.

DESCRIPTION OF THE INVENTION

The bis-(1-halo-2-substituted-thioethyl) sulfones of the invention arerepresented by the formula ##STR1## and thebis-(2-substituted-thiovinyl) sulfones of the invention are representedby the formula

    RSCH = CHSO.sub.2 CH = CHSR                                (II)

wherein R is alkyl of 1 to 6 carbon atoms, phenyl or phenyl substitutedwith 1 to 3 of the same or different substituents selected from fluoro,chloro, bromo or nitro.

Representative alkyl R groups are methyl, ethyl, isopropyl and hexyl.Representative aryl R groups are 2-fluorophenyl, 4-chlorophenyl,3,5-dibromophenyl, 2-nitro-4-chlorophenyl, 2-chloro-4-bromophenyl and2,4,6 -trichlorophenyl.

Preferably R is phenyl or phenyl substituted with 1 to 2 of the same ordifferent substituents selected from fluoro, chloro, bromo or nitro.Most preferably R is phenyl substituted with 1 to 2 chloro, bromo ornitro.

Representative compounds of the invention include:

Bis-(1-chloro-2-methylthioethyl) sulfone,

Bis-(1-bromo-2-ethylthioethyl) sulfone,

Bis-(1-bromo-2-o-fluorophenylthioethyl) sulfone,

Bis-(1-chloro-2-o-chloro-p-bromophenylthioethyl) sulfone,

Bis-(2-methylthiovinyl) sulfone,

Bis-(2-hexylthiovinyl) sulfone,

Bis-(2-o-fluorophenylthiovinyl) sulfone, and

Bis-(2-o-nitro-p-chlorophenylthiovinyl) sulfone.

The bis-(1-halo-2-substituted-thioethyl) sulfones (I) are prepared byadding a sulfenyl halide (III) to divinyl sulfone (IV) and thebis-(2-substituted-thiovinyl) sulfones (II) are prepared bydehydrohalogenating the bis-(1-halo-2-substituted-thioethyl) sulfones(I) with a base, as depicted in the following reactions: ##STR2##wherein R and X have the same significance as previously defined and Bis a base.

Reaction (I) is conducted by reacting substantially 2 moles of thesulfenyl halide (III) per mole of the divinyl sulfone (IV) in the liquidphase at a temperature of about 0° to 100°C. Generally, an inert organicsolvent, such as an alkane, a haloalkane or an aromatic compound isemployed in the reaction. Reaction pressure is suitably atmospheric,subatmospheric or superatmospheric. For convenience, the reactionpressure is generally atmospheric. The reaction is generally exothermicand is completed in about 1 to 24 hours. The bis-(1-halo-2-substituted-thioethyl) sulfone product (I) is isolated and purified byconventional procedures such as extraction, filtration, chromatography,distillation or, alternatively, is used directly in reaction (2) withoutpurification and/or isolation.

In reaction (2), the bis-(1-halo-2-substituted-thioethyl) sulfone (I) istreated with about 2 equivalents of a base. The preferred base is anorganic base such as a pyridine compound, e.g., pyridine or analkylpyridine, or a trialkylamine, e.g., triethylamine. Reaction (2) isconducted in the liquid phase at a temperature of 0° to 100°C.Generally, an inert organic diluent such as a haloalkane, e.g.,dichloromethane or an aromatic hydrocarbon, e.g., benzene, is employedin the reaction. The reaction pressure is not critical, and, forconvenience, the pressure is generally atmospheric. The reaction isgenerally complete within about 1 to 24 hours. The product (II) isisolated and purified by conventional procedures such as filtration,extraction, distillation, chromatography, etc.

UTILITY

The compounds of the invention are useful for controlling fungi,particularly plant fungal infections caused by Botrytis cinerea, leafblights caused by organisms such as Pythrium ultimum, Helminthosporumsativum, Fusarium moniliforme, Rhizoctonia solani, Monolinia fructicolaand Uromyces phaseoli typica. However, some fungicidal compounds of theinvention may be more fungicidally active than others against particularfungi.

When used as fungicides, the compounds of the invention are applied infungicidally effective amounts to fungi and/or their habitats, such asvegetative hosts and non-vegetative hosts, e.g., animal products. Theamount used will, of course, depend on several factors such as the host,the type of fungus and the particular compound of the invention. As withmost pesticidal compounds, the fungicides of the invention are notusually applied full strength, but are generally incorporated withconventional, biologically inert extenders or carriers normally employedfor facilitating dispersion of active fungicidal compounds, recognizingthat the formulation and mode of application may affect the activity ofthe fungicide. Thus, the fungicides of the invention may be formulatedand applied as granules, as powdery dusts, as wettable powders, asemulsifiable concentrates, as solutions, or as any of several otherknown types of formulations, depending on the desired mode ofapplication.

Wettable powders are in the form of finely divided particles whichdisperse readily in water or other dispersant. These compositionsnormally contain from about 5-80% fungicide, and the rest inertmaterial, which includes dispersing agents, emulsifying agents andwetting agents. The powder may be applied to the soil as a dry dust, orpreferably as a suspension in water. Typical carriers include fuller'searth, kaolin clays, silicas, and other highly absorbent, readilywettable, inorganic diluents. Typical wetting, dispersing or emulsifyingagents include, for example: the aryl and alkylaryl sulfonates and theirsodium salts; alkylamide sulfonates, including fatty methyl taurides;alkylaryl polyether alcohols, sulfated higher alcohols, and polyvinylalcohols; polyethylene oxides, sulfonated animal and vegetable oils;sulfonated petroleum oils; fatty acid esters of polyhydric alcohols andthe ethylene oxide addition products of such esters; and the additionproducts of long-chain mercaptans and ethylene oxide. Many other typesof useful surface-active agents are available in commerce. Thesurface-active agent, when used, normally comprises from 1% to 15% byweight of the fungicidal composition.

Dusts are freely flowing admixtures of the active fungicide with finelydivided solids such as talc, natural clays, kieselguhr, pyrophyllite,chalk, diatomaceous earths, calcium phosphates, calcium and magnesiumcarbonates, sulfur, lime, flours, and other organic and inorganic solidswhich act as dispersants and carriers for the toxicant. These finelydivided solids have an average particle size of less than about 50microns. A typical dust formulation useful herein contains 75% silicaand 25% of the toxicant.

Useful liquid concentrates include the emulsifiable concentrates, whichare homogeneous liquid or paste compositions which are readily dispersedin water or other dispersant, and may consist entirely of the fungicidewith a liquid or solid emulsifying agent, or may also contain a liquidcarrier such as xylene, heavy aromatic naphthas, isophorone, and othernonvolatile organic solvents. For application, these concentrates aredispersed in water or other liquid carrier, and are normally applied asa spray to the area to be treated.

Other useful formulations for fungicidal applications include simplesolutions of the active fungicide in a dispersant in which it iscompletely soluble at the desired concentration, such as acetone,alkylated naphthalenes, xylene, or other organic solvents. Granularformulations, wherein the fungicide is carried on relatively coarseparticles, are of particular utility for aerial distribution or forpenetration of cover-crop canopy. Pressurized sprays, typically aerosolswherein the active ingredients is dispersed in finely divided form as aresult of vaporization of a low-boiling dispersant solvent carrier, suchas the Freons, may also be used. All of those techniques for formulatingand applying fungicides are well known in the art.

The percentages by weight of the fungicide may vary according to themanner in which the composition is to be applied and the particular typeof formulation, but in general comprise 0.5 to 95% of the toxicant byweight of the fungicidal composition.

The fungicidal compositions may be formulated and applied with otheractive ingredients, including other fungicides, insecticides,nematocides, bactericides, plant growth regulators, fertilizers, etc.

The compounds of the invention are also useful for controllingmicrobiological organisms such as algae, bacteria, molds andoccasionally aquatic weeds which foul aqueous industrial effluents andcooling streams, such as those occurring in the paper and foodprocessing industries. They may also be used to control such organismsin other aqueous bodies such as lakes, streams, canals, pools and thelike. When so used, a biocidal quantity of one or more of the compoundsof this invention is added to the aqueous growth environment of theorganisms. Usually, this dosage will range between about 0.1 to 50 ppm.In any given instance, the optimum dosage will depend upon theparticular organism and aqueous body involved. For instance, when usedto control algae, these compounds will usually be employed atconcentrations of about 0.1 to 10 ppm. In terms of pounds of compoundper acre of water one foot deep 0.1 to 10 ppm is equal to about 0.3 to30 pounds per acre of water one foot deep. These compounds may beapplied to the aqueous growth environments of such organisms asdispersible powders or in solution with water-miscible solvents.

EXAMPLE 1 Preparation of bis-2-(4-bromophenylthio)vinyl sulfone

Fifteen grams of 4-bromophenylsulfenyl chloride was added slowly to asolution of 3.0 g divinyl sulfone in 30 ml chloroform so there was noexotherm. The reaction mixture was heated under reflux for 21/2 hoursand then stripped. The crude product was treated with 5.2 g oftriethylamine in 40 ml of benzene overnight, then filtered and stripped.The crude product was a red semi-solid showing 3 spots on thin layerchromatography. The crude product, 7.0 g, was chromatographed throughsilica gel (CH₂ Cl₂ eluant) to give 3.2 g bis-2-(4-bromophenylthio)vinyl sulfone as a red liquid. Thin layerchromatography of the product showed a single spot. The product and itselemental analysis is tabulated in Table I as compound No. 3.

The other compounds (except Nos. 9 or 10) tabulated in Table I wereprepared by a procedure similar to that of Example 1.

EXAMPLE 2 Preparation of bis-[ 1-chloro-2-(4 -chlorophenylthio)ethyl]sulfone

4-chlorophenylsulfenyl chloride, 7.6 g, and 2.5 g of divinyl sulfonewere refluxed for 3 hours in 30 ml of methylene chloride. Stripping gavea crude oil showing 4 spots by thin layer chromatography. Purificationwas carried out by chromatography over silica gel. The product waseluted first with methylene chloride and then with 3:1 methylenechloride-acetone to obtain a purified fraction, 3.4 g; calcd. for C₁₆H₁₄ Cl₄ O₂ S₃, S 20.2; found, S 21.5. The product is tabulated in TableI as compound No. 9.

EXAMPLE 3 Mycelial Inhibition

A number of the compounds of the present invention were evaluated forfungicidal effectiveness by means of a mycelial inhibition test. Thistest is designed to measure the fungitoxic activity of fungicidalchemicals in terms of their degree of inhibition of mycelium growth.Each compound to be tested was dissolved in acetone to 500 ppmconcentration. Paper strips were innoculated with the particularmycelium growth by covering the paper with a potato dextrose brothculture of mycelial suspension. The innoculated papers were then placedon potato dextrose agar plates and sprayed by means of a micro sprayerwith the fungicidal solution. The treated paper strips were incubated at25°C and data is taken after 24 hours. Fungicidal activities aremeasured by a zone of inhibited mycelial growth from the center of thepaper strip. The effectiveness of the compounds tested for fungicidalactivity is reported in Table II in terms of the microgram/cm² for 99%control of the fungus.

EXAMPLE 4 Algae Control

Representative compounds of the invention were tested as algicides bythe following method. The algae test species were Lemna, Elodea andSpirolina. An acetone solution of the test compound and a small amountof an alkylarylpolyoxyethylene glycol-containing surfactant wasprepared. This solution was mixed with a nutrient broth in a quantitysufficient to give a concentration of 2 ppm. A 240 ml container wasfilled with this mixture. A sample of the test algae was added to eachcontainer and the container was then placed in an illuminatedenvironment and maintained at a temperature of about 20°C forincubation. The containers were observed periodically for algae growth(as compared to an untreated check). The algicidal effectiveness of thetest compound was determined based on a final observation of algaegrowth after 7 to 10 days. The results of the test on a 0 to 100 basis-- 0 indicating no effectiveness and 100 indicating completeeffectiveness -- are reported in Table III.

    __________________________________________________________________________    Compound of the formula                                                       SO.sub.2 (CH=CHSR).sub.2                                                                           Elemental Analysis                                       Compound      Physical                                                                             Sulfur  Halogen                                          No.     R      State Calc.                                                                             Found                                                                             Calc.                                                                             Found                                        __________________________________________________________________________    1     p-Cl--φ (a)                                                                      liquid  23.9                                                                              22.9                                                                              17.6                                                                              16.2                                         2     m-Cl--φ                                                                          oil     23.8                                                                              23.5                                                                              17.6                                                                              17.7                                         3     p-Br--φ                                                                          oil     19.5                                                                              18.6                                                                              32.5                                                                              33.6                                         4     2,5-Cl.sub.2 --φ                                                                 oil     20.4                                                                              19.0                                                                              30.0                                                                              30.3                                         5     p-F--φ                                                                           m.p. 85-9°C                                                                    25.5                                                                              24.3                                                                              10.3                                                                               9.7                                         6     p-NO.sub.2 --φ                                                                   semi-solid                                                                            22.7                                                                              21.4                                                                              --  --                                           7     3,4-Cl.sub.2 --φ                                                                 oil     20.4                                                                              20.2                                                                              30.0                                                                              29.2                                         8     φ  oil     28.7                                                                              25.3                                                                              --  --                                           9     (b)    oil     20.2                                                                              21.5                                                                              --  --                                           10    (c)    m.p. 143-5°C                                                                   23.6                                                                              23.7                                                                              --  --                                           __________________________________________________________________________     (a) φ = phenyl                                                            (b) bis-[1-chloro-2-(4-chlorophenylthio)ethyl] sulfone                        (c) bis-2-(4-chlorophenylthio)ethyl sulfone                              

    ______________________________________                                        Percent Aquatic Weed Control, %                                               Compound No. Lemna     Elodea    Spirolina                                    ______________________________________                                        1            68        97        --                                           2            100       94         0                                           3            94        94        40                                           4            39        70        80                                           5            30        70        80                                           6            99        78        90                                           7            70        90        95                                           8             0        39        30                                           9            22        22        90                                            10           0         0         0                                           ______________________________________                                    

    __________________________________________________________________________    Mycelia Inhibition                                                            micrograms/cm.sup.2 for 99% control                                                   Pythium                                                                            Rhizoctonia                                                                          Aspergillus                                                                          Fusarium                                                                             Botrytis                                    Compound No.                                                                          ultimum                                                                            solani niger  moniloforma                                                                          cinerea                                     __________________________________________________________________________    1       0.22 0.9    0.86   >1.7   --                                          2       >1.7 1.5    1.1    >1.7   1.2                                         3       >1.7 1.4    0.73   >1.7   1.4                                         4       >1.7 1.2    >1.7   >1.7   0.70                                        5       >1.7 >1.7   >1.7   >1.7   >1.7                                        6       0.73 0.50   0.34   >1.7   0.7                                         7       0.78 0.97   1.1    1.0    0.70                                        8       >1.7 0.88   0.50   >1.7   1.5                                         9       0.65 1.5    1.3    1.3    1.1                                          10     >1.7 >1.7   >1.7   >1.7   >1.7                                        __________________________________________________________________________

What is claimed is:
 1. A compound of the formula

    RSCH = CHSO.sub.2 CH = CHSR

wherein R is alkyl of 1 to 6 carbon atoms, phenyl or phenyl substitutedwith 1 to 3 of the same or different substituents selected from fluoro,chloro, bromo or nitro.
 2. The compound of claim 1 wherein R is phenylor phenyl substituted with 1 to 2 of the same or different substituentsselected from chloro, bromo or nitro.
 3. the compound of claim 1 whereinR is phenyl substituted with 1 to 2 chloro.
 4. The compound of claim 1wherein R is p-chlorophenyl.